The ethics of eating talking plants

In a blog post on The Atlantic Wire, Sara Morrison writes,

“Just when moral vegetarians thought their meal of choice wasn’t sentient, it turns out that plants can totally talk to each other. Even weirder, they communicate through underground fungi. So mushrooms aren’t cool to eat, either. Sorry.”


Because that is how simple moral reasoning is. Morrison assumes, with no evidence, that moral vegetarians base their decisions on whether animals can communicate. This may be because others such as Descartes have denied that animals can have thought without language. Descartes further argued that without thought animals could no more experience suffering than a machine could. Perhaps to make a point, or not, he described some rather vivid scenes of vivisection.

But it is a mistake to think ethical vegetarians are motivated by Descartes’ thinking. We tend to think more along the lines of Jeremy Bentham, who famously said:

“Is it the faculty of reason, or, perhaps, the faculty of discourse? But a full-grown horse or dog is beyond comparison a more rational, as well as a more conversable animal, than an infant of a day, or a week, or even a month, old. But suppose the case were otherwise, what would it avail? the question is not, Can they reason? nor, Can they talk? but, Can they suffer?”


In response to the ethical vegetarian’s focus on suffering, some philosophers such as Daniel Dennett have shown that it is at least possible that animals can experience pain without the attendant suffering that vegetarians assume. It is possible that animals are automata that respond to pain without being aware of it, just as we may roll over in our sleep when we become uncomfortable (Dennett’s example). We can feel the pain and respond to it with no awareness whatsoever. (Interestingly, Dennett seems pretty sure dogs, and no other animals, may experience suffering in an otherwise uniquely human way.)

So, ethical vegetarians are stuck between those who claim that plant communication implies suffering that make moral demands on them and people who deny that clear expressions of pain are conclusive evidence that any given creature actually experiences suffering. For me, I’m quite content to assume that plants are not suffering until they express their suffering in a less ambiguous manner (or someone manages to measure it in a more convincing manner). At the same time, I’m content to assume animals with a nervous system similar to mine and pain expressions similar to mine are experiencing some kind of suffering that is enough to motivate some moral concern on my part.

At any rate, I can’t imagine how an indifference to the appearance of suffering can be something to go around bragging about. (And one final note: I really don’t understand vegetarians who are inexplicably eager to explain that they have no concerns whatsoever about the suffering of sentient beings but are only trying to lose weight or something.)

Cartesian Ethics: Concern for Self and Others

Cartesian Ethics: Concern for Self and Others

When examining the ethics of Descartes, it is easy to focus exclusively on his interest in virtue and concern for self-interest. As a result, discussions of his ethics often have what Cecilia Wee called “a persistent image of the Cartesian agent as a selfish or egoistical individualist” (255) in her essay titled “Self, Other, and Community in Cartesian Ethics.” According to Descartes, by using reason to understand the nature of God and the moral order of the universe, humans are able to control their passions and accept their fate in life with equanimity. We may not be happy in the sense of being exuberant. Rather, the virtuous person is rewarded with a “satisfied mind.” Virtue and contentment is not the end of the story, however. In a typical description, Donald Rutherford describes Cartesian ethics in this manner:

In agreement with the ancients, he takes philosophy’s practical goal to be the realization of a happy life: one in which we enjoy the best existence that a human being can hope to achieve. Descartes characterizes this life in terms of a type of mental flourishing, which he calls “contentment of mind,” or “tranquility.” Here the influence of Stoic and Epicurean ethics is evident. (1)

In Descartes’s philosophy we find some echoes of previous moral views such as the virtue ethics of the ancients, but we also see that Descartes anticipated many modern moral theories, including Kant’s respect for persons and utilitarianism.

Many have lamented the fact that Descartes was never able to develop his moral theory in the formal manner of his metaphysics and epistemology. There is no cause for despair, however, as Descartes has left us plenty of grist for the grind. If we take as a given that the aim of philosophy is to enable us to live better lives, we cannot only examine Descartes’s comments on morality, but we must also evaluate how his metaphysical and epistemological claims promote eudaimonia. By this, we do not mean to see whether Descartes has found a way to make us all happy but whether he promotes a sense of being better off and flourishing, for it is clear that cheerfulness is not the supreme good. He writes to Princess Elizabeth, “Seeing that it is a greater perfection to know the truth than to be ignorant of it, even when it is to our disadvantage, I must conclude that it is better to be less cheerful and possess more knowledge” (CSM III, 268).

In this, we can see that epistemological concerns have a moral dimension for Descartes, so it is appropriate to evaluate his epistemology from a normative standpoint. His epistemology, of course, rests on his metaphysical assumptions. For the purposes of this paper, I will take his metaphysical assumptions as discoveries that are proven through his writings. He counsels Elizabeth that although there are many things we cannot know, we must content ourselves with the most useful truths. Most importantly, he argues that “there is a God on whom all things depend, whose perfections are infinite, whose power is immense, and whose decrees are infallible” (CSM III, 265).

If we take Descartes at his word and accept that the provisional morality expressed in the Discourse is truly provisional, then the value of examining his comments there is dubious. On one view, the provisional morality is nothing more than a literary or rhetorical device designed to heighten excitement for the epistemological project. The need to take a provisional morality implies that skepticism is extremely risky. With the proper preparation, however, one can be sure to make things no worse than they are. Descartes reassures his readers both that he is doing something extremely bold and also that he is taking no chances with the stability of society and morality. Descartes is giving his promise that he will not abandon all standards of behavior while completing the skeptical experiment. On the other hand, he does seem to be claiming that the provisional morality is good enough for himself until his metaphysical and epistemological foundations can be established.

Further, he suggests that others may choose to embark on a similar project, so he seems to be endorsing his provisional morality for anyone with the proper will and disposition for the project. Excluded from the endeavor, as he notes in the Discourse, are those who believe themselves “cleverer than they are” so that they judge too hastily and those who recognize they are better to “follow the opinions of others rather than seek better opinions themselves” (CSM I, 118). For himself, and anyone wishing to follow his lead, he laid out “three or four” maxims. The confusion over the number may stem from the fact that the fourth is more of a decision than a maxim.

One value of the Cartesian metaphysical project is that it gives a sense of serenity in knowing we only accept what is certain as true. We can know that there is a good God, free will, and a moral order to the universe. Since God is perfect, we know we are never being deceived. We also know that God does not create evil, as evil is not a thing. Further, we know that we can always choose what is good and correct. Error is the result of will, not intellect, which derives truth from God.

Descartes’s metaphysical argument regarding evil and free will is, unfortunately, incoherent. The problems with his view of humans become apparent when compared to the lives of animals, angels, and the human mind when separated from the body. Animals, lacking free will or intellect, act in a perfect manner and are not capable of evil. In his early writing, he says, “The high degree of perfection displayed in some of their actions makes us suspect that animals do not have free will” (CSM I, 5). Of course, animals also lack moral agency and are of no concern morally. The suffering animals endure has no moral significance. He makes this point distressingly clear when he describes a vivisection by saying, “If you slice off the pointed end of the heart in a live dog, and insert a finger into one of the cavities, you will feel unmistakably that every time the heart gets shorter, it presses the finger” (CSM I, 317). An animal’s behavior is never to be faulted. However, it also should never be praised.

Angels, lacking bodies, are not subject to the errors that arise from preconceived opinions. Angels do not contain all the perfections of God, else they would be God, but they are immune from the confused and obscure thinking that plagues those of us burdened with sensation. Their ideas must be clear and distinct, as they are pure intellect. In a letter to Chanut, Descartes declares, “We regard the least of the angels as incomparably more perfect than human beings” (CSM III, 322). Angels also have free will. They are not part of the mechanistic material of the universe. Given that angels have free will along with an intellect that is not clouded by obscure and confused ideas, it is difficult to see why the existence of humans in the universe is of any value.

Humans are burdened with an infinite will, a finite intellect, and an unreliable body that gives rise to false opinions. Through great effort, humans are able to enumerate and simplify their ideas until they are left only with clear and distinct ideas that are true and certain. This process of elimination of error from the human mind is supposed to be of obvious value. By coming to certain knowledge, we are able to make accurate and positive judgments, and these result in proper virtue. This is the source of esteem for humans. In The Passions of the Soul, he writes, “I see only one thing in us which could give us good reason for esteeming ourselves, namely, the exercise of free will and the control we have over our volitions. For we can reasonably be blamed only for actions that depend on this free will. It renders us in a certain way like God by making us masters of ourselves, provided we do not lose the rights it gives through timidity” (CSM I, 384). Here Descartes seems to imply that angels, “incomparably more perfect” than humans, are less praiseworthy since they need not struggle against the limitations of the physical body. In this case, it is not clear why we should consider it a blessing to be praiseworthy.

Being more perfect seems to be a good alternative to being praiseworthy, as being capable of praise brings with it a host of afflictions. Having a soul connected to a body and a body whose actions are imperfect as a result of free will leads to no small amount of suffering. For Descartes, this is not cause for alarm or self-pity.

Rather than feeling remorse over the afflictions and inconveniences of life, Descartes sees things differently. In a letter to Princess Elizabeth, he says, “There is a God on whom all things depend, whose perfections are infinite, whose power is immense and whose decrees are infallible. This teaches us to accept calmly all things which happen to us as expressly sent by God” (CSM III, 265). Given that suffering results from the soul being connected to body, it may seem that God is responsible for evil, but Descartes rejects this notion as well. God is not the author of evil, because evil is not a thing. In the Principles, Descartes claims that God is the source of all things, but he hastens to assure us, “When I say ‘everything,’ I mean all things: for God does not will the evil of sin, which is not a thing” (CSM I, 201). Sin is, rather, the result of bad judgment and movement of the will. God could have given us perfect judgment, but “we have no right to demand it of him . . . we should give him the utmost thanks for the goods which he has so lavishly bestowed upon us, instead of unjustly complaining that he did not bestow on us all the gifts which it was in his power to bestow” (CSM I, 205). Humans are the authors of and remedies for evil.

Evil is only a privation of our perfections, rather than a thing created by God. This scholastic account of evil is a rather cold comfort for the miserable wretch suffering a multitude of afflictions. Still, even contemporary theologians offer us the same reassurance. John Hick, for example, tells us that the world without suffering might be quite pleasurable, but it would be “very ill adapted for the development of the moral qualities of human personality. In relation to this purpose, it would be the worst of all possible worlds” (115). This ignores the possibility of a universe with neither pleasure nor pain—a universe with no sentient life.

Arthur Schopenhauer, under the influence of Indian religious and philosophical writings, sees this scholastic view of evil as being completely backward. He says, “I therefore know of no greater absurdity than that absurdity which characterizes almost all metaphysical systems: that of explaining evil as something negative. For evil is precisely that which is positive, that which makes itself palpable; and good, on the other hand, i.e. all happiness and all gratification, is that which is negative, the mere abolition of a desire and extinction of a pain” (42). Taking a moral framework that seems diametrically opposed to the view of Descartes, Schopenhauer sees compassion as the greatest moral good. He says:

Boundless compassion for all living beings is the firmest and surest guarantee of pure moral conduct, and needs no casuistry. Whoever is inspired with it will assuredly injure no one, will wrong no one, will encroach on no one’s rights; on the contrary, he will be lenient and patient with everyone, will forgive everyone, will help everyone as much as he can, and all his actions will bear the stamp of justice philanthropy, and loving kindness. (229)

Further, Schopenhauer points out that it would seem illogical to claim that a person was unjust and immoral and still claim that person to be very compassionate. In this way, morality supervenes on compassion. At first look, it appears Schopenhauer has made a huge departure from the kind of morality perceived by Descartes (this is confirmed if we look at their views of animals), but Descartes makes some statements that are surprisingly similar. In following passage, Descartes almost appears to be a precursor to Schopenhauer:

Those who are generous in this way are naturally led to do great deeds, and at the same time not to undertake anything of which they do not feel themselves capable. And because they esteem nothing more highly than doing good to others and disregarding their own self-interest, they are always perfectly courteous, gracious, and obliging to everyone. Moreover, they have complete command over their passions. (CSM I, 385)

We might object, though, that Descartes is merely advocating compassion as an appropriate emotion or virtue. He may not be arguing that we should set aside our self-interest for others. Descartes is often viewed as an egoist and virtue ethicist (Wee 255). There is plenty of textual evidence to support such a claim, but it is also clear that putting the interests of others out of compassion or duty is, in itself, a virtue. He makes this clear in a letter to Princess Elizabeth:

That each of us is a person distinct from others, whose interests are accordingly in some way different from those of the rest of the world, we ought still to think that none of us could subsist alone and that each one of us is really one of the many parts of the universe, and more particularly a part of the earth, the state, the society, and the family to which we belong by our domicile, our oath of allegiance, and our birth. (CSM III, 266).

In our pursuit of virtue, which is in turn a pursuit of the good life, we must be compassionate and, at least occasionally, put the interests of others ahead of our own interests. In this regard, Descartes takes a step toward the utilitarian theories of Bentham, Hume, Mill, and even contemporary philosophers such as James Rachels and Peter Singer. We will not go so far as to claim Descartes is an early utilitarian, but we can see the rudiments of utilitarian thought in a these passages.

Descartes’s ideas on moral agency also predicted later ethical theories. The material universe, for Descartes, is a mechanical system governed by necessary physical laws. Humans are in a unique position in this universe as humans are the only beings possessing both body and mind. When we consider the interests of others, we consider only the interest of those who are worthy of esteem and blame, i.e. humans. As John Marshall puts it in his book, Descartes’s Moral Theory, “Because they possess intelligence and will, others merit our esteem as beings of a certain kind, beings having the potential for a specific kind of development, both intellectual and moral” (152). Simply possessing free will gives one the potential for virtue, which deserves respect. Because all humans have intellect and will, we must treat them with a measure of respect, even if they behave badly. As mentioned above, Descartes tells us that we are only worthy of praise or blame because we have control over our volitions. This control makes us somewhat like God by “making us masters of ourselves” (CSM I, 384). Thus, all humans deserve respect, but it is only through the intellect and the will that humans choose appropriate actions. Animals, of course, are not capable of such actions, so all humans are in a special category of respect. Even animals can be trained, he says in article 50 of the Passions, to have some control over their impulses. They are not acting rationally, of course, but merely responding to training. He says, “For since we are able, with a little effort, to change the movements of the brain in animals devoid of reason, it is evident that we can do so still more effectively in the case of men. Even those who have the weakest souls could acquire absolute mastery over all their passions if we employed sufficient ingenuity in training and guiding them” (CSM I, 348).

This interplay of reason and will, available only to humans, sounds similar to more modern ethical theories, especially those related to Kant and his categorical imperative. Rutherford describes the relationship by noting Cartesian ethics “is crowned by a principle of moral universalism: in virtue of their free will, all human beings have the same moral status and deserve equal moral respect. In this we find an important anticipation of Kant’s ethics, which emerges from a similar consideration of the unconditional value of a rational and free will” (12).

For Kant, our intellectual abilities and virtues of courage, resolution, and so on will be of no value if our will is mischievous. Rather than saying a good will and rationality will make us happy, he says, “A good will appears to constitute the indispensable condition of being worthy of happiness” (445). This echoes Descartes’s claim that we are praiseworthy when our will chooses what is evident to the intellect. Kant also insists that moral thought “is only possible in a rational being, in so far as this conception, and not the expected effect, determines the will” (448). It is only humans who receive praise or blame for their actions, and concern for non-human beings is of no moral significance. Kant says, “Beings whose existence depends not on our will but on nature’s, have nevertheless, if they are irrational beings, only a relative value as means, and are therefore called things; rational beings, on the contrary, are called persons, because their very nature points them out as ends in themselves” (452). Non-human beings are of concern only with regard to what goods they can provide humans. Kant would, of course, have no objection to the vivisection described by Descartes.

On the question of suicide, Descartes and Kant take a different approach, but it seems unlikely that Descartes would object to Kant’s argument. First Descartes tells Princess Elizabeth that suicide is to be avoided because “natural reason teaches us also that we have always more good than evil in this life, and that we should never leave what is certain for what is uncertain. Consequently, in my opinion, it teaches that though we should not seriously fear death, we should equally never seek it” (CSMK 276). In contrast, Kant claims that anyone who seeks suicide would be acting from a self-contradiction. He says, “Now we at once see that a system of nature of which it should be a law to destroy life by means of the very feeling whose special nature it is to impel to the improvement of life would contradict itself, and, therefore, could not exist as a system of nature” (450). Kant’s rational argument would surely not contradict Descartes’s vision of will, intellect, and virtue.

Descartes’s position in the history of normative ethics is similar to his position in the history of philosophy as a whole. Although he set out to establish a new philosophy, he never fully broke with the ancients of the scholastics. Still, he broke new ground and provided fertile fields to be plowed and cultivated by thinkers such as Schopenhauer, Bentham, Mill, and Kant. Even if Descartes was not able to provide a fully developed account of how we should live, he gave considerable details as to what the good life is and how it can be achieved. Rather than trying to determine what his ethical system might have been, philosophers might be better served by trying to determine how Descartes’s ideas can serve contemporary ethical theories. We must be committed to the idea that philosophy can make life better, and Descartes at the very least provides sufficient detail for us to ponder his larger questions.


Works Cited

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—. The Philosophical Writings of Descartes: Volume II. Trans. John Cottingham, Robert Stoothoff, and Dugald Murdoch. Cambridge: Cambridge UP, 1985.

—. The Philosophical Writings of Descartes: Volume III. Trans. John Cottingham,

Robert Stoothoff, Dugald Murdoch, and Anthony Kenny. Cambridge: Cambridge

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William Lawhead. Boston: McGraw Hill, 2003. 111-16.

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Marshall, John. Descartes’s Moral Theory. Ithaca: Cornell UP, 1998.

Rutherford, Donald, “Descartes’ Ethics”, The Stanford Encyclopedia of Philosophy

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Wee, Cecilia. “Self, Other, and Community in Cartesian Ethics.” History of Philosophy

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